Induction-coil.



M. M. WOOD. INDUCTION COIL.

APPLIOATION FILED NOV. 15, 1904.

Fig. I 2.0 l9 8 7 I F E 2E I a r 8 Witnesses. lnveht-or; 5/3Montrclville M. Wood.

PATENTED JUNE 5, 1906.

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UNITED STATES PATENT onnron.

MONTRAVILLE M. WOOD, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INDUCTION-COIL.

Specification of Letters Patent.

'ratenteo'i June 5, 1906.

To all whom it may concern:

Be it known that I, MONTRAVILLE M. WOOD, a citizen of the United States,resid ing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Induction- Ooils, ofwhich the following is a specification.

It is the object of the resent invention to provide an induction-coi ortransformer suitable for transforming electrical energy, andparticularly for transforming small quantities of power foruse inresistance measurements and similar operations. The windings of theinduction-coil are in the form of helices, and one of the windingsconsists of a bare conductor so arranged that the outer edge may be usedas a contact-surface for an adjustable contact-wheel. The other windinghas the peculiarity of consisting in whole or in part of a conductorhaving magnetic propertiessuch, for instance, as ironwith a view toutilizing these magnetic properties to strengthen the magnetic fluxthrough the coils.

In the accompanying drawings, Figure 1 is an elevation of my improvedform of induction-coil mounted on a suitable support and provided withcollector-rings and with a contact-wheel for the bare conductor andmeans for rotating the induction-coil to move the contact-wheel alongthe edge of the bare conductor. Fig. 2 is a partial transverse sectionof the coil with the end-caps removed. Fig. 3 is a transverse section ofthe same. Fig. 4 is a detail view ofthe contact-wheel.

The rimary or low-potential winding 1 of the in notion-coil mnsists',preferably, of a bare edge-wound conductor arranged 1n the form of ahelix and connected at its terminals to the collector-rings 2 and 3.Through the center of this helix extends a tube 4, of mica or otherinsulating material, within which is a group of iron wires 5, insulatedfrom each other with silk or other good insulating material. The wiresare arranged within the insulating-tube 4, but outside of a smallerinsulating-tube 6, as shown in Fig. 3. Within this inner insulating-tube6 is the usual iron core, consisting of soft-iron rods 7 of the kindcommonly used in such appara- A shaft 8' passes through the center ofthis core and serves as a means for rotating the induction-coil aboutits central axis. A cord 9, of insulating material, isplaced between thesuccessive turns of the winding 1 and serves to suitably space thesuccessive turns. The secondary winding is wound in the helical slotformed by the successive turns of the edge-wound primary; but as it isdesirable to have many more turns in the secondary than in the primarysome special means is neces sary for preserving the continuity of thissecondary winding. Thus if the .conductor passes in at theright-hand endof the spiral, as shown at 10 in Fig. 2, it will finally come out in theleft-hand slot 11, and some provision must be made for returning it tothe right-hand end of thecoil. To accomplish this return, I solder orotherwise connect the end which emerges from slot 11 with one of theinsulated iron conductors 5, thus com leting the circuit to therighthand end of t e coil and permitting a repetition of the windingthroughout the length of the helical slot until the desired number ofsecondary turns has been obtained. The insulated iron wires 5 conductormay consist of copper, though this construction can be made only at thesacrifice of the magnetic path afforded by the iron wires 5. To theterminals of the secondary winding are connected two collector'- rings12 and 13 for connecting the coil in circuit, and insulating-caps 22 23'protect the ends of the coils from injury. Suitable standards 14 and 15,mounted on the base 16,

support the shaft 8 and permit the inductioncoll-to be rotated by meansof a crank 17, secured at oneend of the shaft 8. A contactroc wheel 18is supported loosely on the rod 19,

joining the two standards, and is adapted to rotate in contact with theouter edge of the primary winding 1 and at t e same time to movelongitudinally on the'rod 19, and thus move progressively from one turnof the winding to the next as the coil is rotated by means of the crankA conductor 20 is power or test circuit.

connected to the rod 19, and thus serves as a means for connecting thewheel 18 with a If current is supplied through the slip-ring 3 and wheel18, any desired pressure may be secured at the high-potential terminalsby varying the ratio of transformation of the transformer by turning thecrank 17. The contact-wheel 18 is provided with a plurality of slots 21,filled with mica or other insulating material, so that if direct currentis supplied through conductor 20 the contact-wheel will automaticallymake and break the circuit as the wheel moves along the edge of theprimary conductor, and thus generate an alternating current in thehigh-potential winding of the transformer. The four slip-rings furnish aready means for connecting the transformer in a variety of ways for testpurposes, and while I contemplate using the device herein described formeasuring the resistance of railjoints on electric roads it is obviousthat it may be used for a great variety of purposes.

Although the novel forms of the windings herein described are believedto be well adapted for use in transformers and inductioncoils, I do notwish to be limited to such specific use, as such windings may be used toadvantage in a great variety of ways, as will be readily understood bypersons skilled in the art.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is

1. A composite winding, comprising anedge-wound conductor in the form ofa helix, and a circular conductor lying between successive turns of saidhelix.

4 2. A composite winding, comprising an edge-wound conductor in the formof a helix, and a winding lying between successive turns of said helixand having a return portion in the space inclosed by said helix.

3. An electrical winding having a part in the form of a helix andhaving-a second part consisting of magnetic material and extendingthrough the space inclosed by said helix.

4. An electrical winding having a part comprising a plurality of turnsand a second part consisting of a plurality of magnetic conductors ininductive relation to said turns form of a helix, and a second windingfor sald transformer, said second winding having a plurality of turnsbetween successive turns of said helix and having a return portionthreading through said helix from end to end.

7. A transformer having a primary winding, and a secondary winding ininductive relation thereto, said secondary winding consisting in part atleast of magnetic material and having a portion lying in the path of themagnetic flux which threads said winding, said portion extendingsubstantially from end to end of said primary winding.

8. A transformer having a winding and means for establishing a magnthrough, said winding consisting in part at least of magnetic materialarranged to furnish a continuous path of high permeability for saidmagnetic flux.

9. In a transformer, a winding, one part of which is in the form of ahelix-and a second part of which has a high magnetic ermeability andextends longitudinally t ough said helix. I

10. In a transformer, a primary winding wound in the form of a helix,and asecondary winding having one part in the form of a helix and lyingbetween the successive turns of said primary winding, and a second partthreading longitudinally through said helices and consisting of aplurality of conductors of magnetic material'insulated from each other.

In witness whereof I have hereunto set my hand this 14th day ofNovember, 1904.

MONTRAVILLE M. WOOD. Witnesses:

ALEx. F. MACDONALD, HELEN ()nronn.

